Tailoring the Morphology of MoS ₂ using RF Magnetron Sputtering for Enhanced Photoelectrochemical Water Splitting

ABSTRACT 2D molybdenum disulfide (MoS 2 ) is a promising material for optoelectronic and photoelectrochemical (PEC) applications due to its unique properties. This study investigates how adjusting the RF magnetron sputtering power can tailor the morphology of nanostructured MoS 2 and enhance its PEC water‐splitting performance. Structural analysis confirmed the formation of the 2H semiconducting phase, with crystallite sizes increasing from approximately 10 to 32 nm as sputtering power rose. High‐resolution microscopy revealed characteristic interlayer spacings, while Raman spectroscopy verified the material's purity and bulk nature. Surface morphology evolved from granular to vertically aligned nanowall structures with increasing power, and energy‐dispersive spectroscopy showed near‐stoichiometric composition at 180 W. Optical measurements indicated that the bandgap widened from 0.87 to 1.59 eV as power increased. The MoS 2 photoanode synthesized at 180 W achieved the highest photocurrent density (∼5.34 mA/cm 2 ), reflecting superior PEC activity. Mott–Schottky analysis showed a shift in flat‐band potential and a high carrier density, suggesting improved charge separation. Overall, optimizing the sputtering power produced MoS 2 nanosheets with excellent structural, optical, and electrical properties, making them strong candidates for efficient PEC water‐splitting applications.